Electrical connector and connection made therewith



NOV. 8, 1966 5 H N ET AL 3,284,759

ELECTRICAL CONNECTOR AND CONNECTION MADE THEREWITH Filed May 25, 1964 8O 79 75 so 7T l INVENTORS i STEPHEN N. BUCHANAN .1 72 CLARK A. MATHIS l l BYaJ/ M W ATTORNEYS United States Patent 3,234,759 ELECTRIKIAL CONNECTOR AND CONNECTION MADE THEREWITH Stephen N. Buchanan and Clark A. Mathis, Washington, DC, assignors, by mesne assignments, to Stephen N. Buchanan Filed May 25, 1964, Ser. No. 369,868 4 Claims. (Cl. 339252) of them perform their connecting function more or less satisfactorily, they practically all require a tool of some sort, in addition to a conductor stripping tool, to make a connection. This tool either enables the user to place a special lug of some sort on the end of the conductor to be connected, for example bycrimping the lug to the conductor, or it crimps or otherwise fastens the conductor directly to the connector. In the lug type of connector, it is often necessary to perform the further step of placing a nut or a bolt through or over the lug and turn it to secure the lug to the connector.

It is an object of the present invention to provide an device, and yet which will hold a single conductor or a plurality of conductors so securely that the conductor will ordinarily break before it pulls out of the connector.

It is a further object of the present invention to provide an electrical connector to which a stripped conductor can be connected by hand without the use of any tools.

These objects are accomplished by a connector according to the present invention which comprises a post member and one or more coil spring members tightly wound around said post member. One or the other or both the post member and the coil spring member are of a conductive material, and the ends of the spring member are secured to the post member. The middle of the spring member has a bent back portion. A conductor, for example a wire, can be passed around the bent back portion of the coil and bent back on itself to form a loop around the bent back portion and then rotated around the post to slide it down the coil spring member. After it has passed along the spring member, it will be tightly engaged between the coil and the post and between the coil and adjacent coils on either side of it.

The details of the invention will be set forth more fully in connection with the accompanying drawings, in which:

FIG. 1 is an elevational View of an embodiment of the connector according to the present invention;

FIG. 2 is a reduced size plan view of an arrangement of a plurality of connectors similar to those shown in FIG. 1; and

FIG. 3 is an elevation view similar to FIG. 1 showing a modified embodiment of the connector as shown in FIG. 1.

In the embodiments of FIGS. 1-3 a coil intermediate the ends of the spring is bent back on itself and the rest of the spring is coiled in the opposite direction. As seen in FIG. 1, the connector comprises a post member in the form of a post 60 and a coil spring member, generally designated 61. Either the post or the spring, or both, are of a conductive material, such as brass for the post and spring steel for the spring. The spring member 61 has one or more first coils 62 tightly wound around the post 60 in one direction and one or more second coils 63 tightly wound around the post in the other direction. The spring member has a third coil member having one part 64 extending partly around the post in one direction and another part 65 extending partly around the post in the other direction. The center part of the third coil is bent back on itself at 66 and the bent back part is also spaced outwardly of the post 60. The ends 67 and 68 of the first and second coils 62 and 63 which are remote from the third coil are bent over and project into a slot 69 in the post 60 so as to prevent the coil spring member from rotating around the post, but so as to permit movement along the post member.

A conductor, such as wire 70, can then have the end thereof stripped and bent over and hooked under the bent back center part 66 and then moved around the post 60. In FIGURE 1 the conductor 70 is shown as having been rotated around the post one and one-half times, so that the wire passes under four coil portions and consequently is held against the post at four points. The coils of the spring member are against each other, so that in addition to being held between the coils and the post, the wire will also be held between the outermost coil under which it extends and the next adjacent coil in the outward direction from the bent back third coil. A conductor 70a is shown in the position where it has just been placed under the portion of the spring.

It will be noted that each end 91 of the outermost coils from which the bent over ends 67 and 68 extend is also bent slightly away from the coil which is next adjacent said outermost coil. The purpose of this is to provide a slight additional length of coil so that when a wire is inserted under the coils of the spring member, the coils under which it passes will be expanded in the peripheral direction, and the additional length of coil needed for this expansion is taken from this slightly bent end portion. This has the effect of pulling these end portions 91 tight and causing bent over ends 67 and 68 to slide along the slot 69 until the end portions 91 lie against the next adjacent coil.

One manner of utilizing the connector as shown in FIG. 1 is shown in FIG. 2. A pair of blocks 71 of insulating material are adapted to be fastened to a supporting structure, such as a terminal board, by conventional fastening means such as screws 72.

Extending between the two blocks 71 is a rod 73 of insulating material on which is a plurality of spaced discs 74 of insulating material. Around the rod '73 between each pair of discs 74 is a fixed hollow post member 75 of conducting material, which post member has a slot 76 therein. Wrapped tightly around the hollow post member 75 is a coil spring member 77 each half of which is similar to the coil spring member of FIG. 1, but the bent back center parts 78 and 79 face in opposite directions around the post member 75. The ends of the coil spring member are bent over to engage in the slot 76 so as to keep the coil spring from rotating around the post member.

In order to assemble the connectors shown in FIG. 2, the rod 73 is inserted into one of the blocks 71 and a first post member is placed over the rod. A disc 74 is placed on the rod against the end of the first post member, and a second post member is placed on the rod with the end against the disc. A coil spring member is slid down over the second post member with the bent over ends engaged in the slot 76. Another disc 74 is then slid over the rod against the end of the second post member, another post member is placed on the rod and another spring is placed on this post member. This process is repeated until the desired number of springs have been positioned on the rod or the rod is full. Then the other end of the rod is positioned in the other of the blocks 71 and the blocks are secured to a terminal board or the like.

In use, all that is necessary to do to attach conductors 80 to the connectors is to bend the stripped ends of the conductors over and engage them under the bent back portions 78 and 79 and move them around the post members part way. Since one of the bent back portions 78 faces one way around the post member and the other bent back portion 79 faces the other way around the post member, when the conductors 80 are moved part way around the post member, one of the conductors will extend in one direction laterally of the rod and the other conductor will extend in the other direction laterally of the rod. The connectors as thus arranged can therefore be used as a terminal block to attach a series of pairs of conductors to each other at a single location.

The spring member 77 of FIG. 2 need not be made in one piece. As shown in FIG. 3, it can be made as two separate spring members 81 and 82, the spring 81 being identical to the spring member 61 in FIG. 1, and the spring 82 being the same as the spring member 61 in FIG. 1 except that it is wound in the opposite direction so that the bent back portion 83 faces in one direction around the post member 84 and the bent back portion 85 of the spring member 81 faces in the other direction around the post member 84.

It will of course be understood that more than one conductor can be inserted under the bent back portions of the coil spring members of the embodiments of FIGS. 1-3, so that two conductors can be connected to a single coil spring member 61 in FIG. 1, or spring members 81 and 82 in FIG. 3, or two conductors can be connected to a part of the coil spring member 77 of FIG. 2. In the single spring members of FIGS. 1 and 3, when two or more conductors are connected thereto, it is preferable that they be led away from the connector in substantially the same direction.

It is also possible to use only a single spring member such as that of FIG. 1 between each pair of discs in FIG. 2 and to connect two conductors under the single spring members such as that of FIG. 1 between each pair of discs in FIG. 2, so that only a single conductor need be connected to each spring member. Other permutations and combinations of the springs and discs will occur to those skilled in the art.

It is thought that the invention and its advantages will be understood from. this foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

We claim:

1. An electrical connector, comprising a post member and at least one coil spring member, at least one of said members being of an electrically conductive material, said coil spring member having at least one first coil tightly wound around said post in one direction and at least one second coil tightly wound around said post in the other direction, and a third coil extending partly around said post in one direction and partly around said post in the other direction and having a part bent back on itself joining the parts of said third coil, said bent back part having at least the bent portion relatively freely related to said post, said post having a slot along the length thereof and the remote ends of the first and second coils on said spring being bent over and extending through said slot for engaging said spring and said post for preventing relative movement of the post and the spring in the direction around said post, whereby when an elec trical conductor is placed under the bent back part of said third coil and moved around said post member so that it slides along the parts of the third coil which extend in opposite directions and along the first and second coils, it is held in tight engagement between at least the parts of said third coil and said post by the radial inward forces exerted by the parts of the coil on said post and by the frictional force existing between the post, the coil parts, and the conductor.

2. An electrical connector, comprising at least two blocks of insulating material, said blocks being adapted to be attached to a supporting structure, a rod of insulating material extending between said blocks, a plurality of discs of insulating material at spaced intervals along said rod, a hollow post member around said rod between each pair of spaced discs, at least one coil spring member around each said hollow post member, each said coil spring member having at least one first coil tightly wound around said post in one direction and at least one second coil tightly wound around said post in the other direction, and a third coil extending partly around said post in one direction and partly around said post in the other direction and having a part bent back on itself joining the parts of said third coil, said bent back part having at least the bent portion spaced outwardly of said post, the remote ends of said first and second coils being engaged with said post for preventing movement of said coils and around said post, whereby when an electrical conductor is placed under the bent back part of said third coil and moved around said post member so that it slides along the parts of the third coil which extend in opposite directions and along the first and second coils, it is held in tight engagement between at least the parts of said third coil and said post by the radial inward forces exerted by the parts of the coil on said post and by the frictional force existing between the post, the coil parts, and the conductor.

3. An electrical connector as claimed in claim 2 in which the bent back coil of the spring between one pair of discs faces in one direction around said post and the bent back coil of the spring between another pair of discs faces in the other direction around said post.

4. An electrical connector as claimed in claim 2 in which there are at least two spring members between a pair of spaced discs, the bent back coil of one of the springs facing in one direction around said post and the bent back coil of the other spring facing in the other direction around said post.

References Cited by the Examiner UNITED STATES PATENTS 1,152,705 9/1915 Churchill 339254 2,370,857 3/1945 Gunzburger 339-260 X 3,066,274 11/1962 Ellis 339254 X EDWARD C. ALLEN, Primary Examiner.

JOSEPH D. SEERS, Examiner.

P. TEITELBAUM, Assistant Examiner. 

1. AN ELECTRICAL CONNECTOR, COMPRISING A POST MEMBER AND AT LEAST ONE COIL SPRING MEMBER, AT LEAST ONE OF SAID MEMBERS BEING OF AN ELECTRICALLY CONDUCTIVE MATERIAL, SAID COIL SPRING MEMBER HAVING AT LEAST ONE FIRST COIL TIGHTLY WOUND AROUND SAID POST IN ONE DIRECTION AND AT LEAST ONE SECOND COIL TIGHTLY WOUND AROUND SAID POST IN THE OTHER DIRECTION, AND A THIRD COIL EXTENDING PARTLY AROUND SAID POST IN ONE DIRECTION AND PARTLY AROUND SAID POST IN THE OTHER DIRECTION AND HAVING A PART BENT BACK ON ITSELF JOINING THE PARTS OF SAID THIRD COIL, SAID BENT BACK PART HAVING AT LEAST THE BENT PORTION RELATIVELY FREELY RELATED TO SAID POST, SAID POST HAVING A SLOT ALONG THE LENGTH THEREOF AND THE REMOTE ENDS OF THE FIRST AND SECOND COILS ON SAID SPRING BEING BENT OVER AND EXTENDING THROUGH SAID SLOT FOR ENGAGING SAID SPRING AND SAID POST FOR PREVENTING RELATIVE MOVEMENT OF THE POST AND THE SPRING IN THE DIRECTION AROUND SAID POST, WHEREBY WHEN AN ELECTRICAL CONDUCTOR IS PLACED UNDER THE BEND BACK PART OF SAID 